Sampling pumps that are widely used for respiration monitoring in medical equipment or modules, such as gas measurement modules, can extract a gas sample from a patient's breathing circuit and convey the extracted gas to respiration monitoring equipment, so that the respiration monitoring equipment can monitor the composition of the gas exhaled by the patient in real time, thereby allowing medical staff to evaluate the patient's vital signs. The gas sensor probe for gas measurement used in respiration monitoring equipment is a precision instrument, and its measurement accuracy can be affected by vibrational interference that may be present during operation. The sampling pump is often a main vibration source in the respiratory monitoring module. The gas sensor can also be sensitive to flow fluctuations of the monitored gas. If the gas sensor experiences large flow fluctuations, some measurement noise may occur, which can also affect measurement accuracy. Therefore, the sampling pump should provide stable sampling flow.
A diaphragm sampling pump using a single rotary motor is often used for gas sampling in existing respiration monitoring equipment. Due to its working principle, the diaphragm pump usually has both relatively large flow fluctuations and some vibrations during sampling. A single linear reciprocating pump may produce larger vibrations, and thus it is not typically used in respiration monitoring equipment.